1. Field of the Invention
The present invention relates to a remote control device configured to operate an industrial machine such as a machine tool, a textile machine, and a transportation device.
2. Description of the Related Art
An industrial machine such as the machine tool, a textile machine, and a transportation machine is configured so as to be operable by a person via a remote control device connected by a cable. The remote control device for operating the machine tool, for example, operates a stage or a loader by use of a rotary encoder. The rotary encoder outputs two signals of an A output and a B output, and the signals are input to a control board of the machine tool (the industrial machine) through the cable.
Since such a wired remote control device is connected to a main body of the industrial machine via the cable, a field of activities of an operator is limited by the cable, and furthermore, there is an inconvenient aspect in that care must be taken to handle the cable. A use of wireless communication is thus considered.
Upon employment of the wireless communication, it is considered that, for example, sampling the pulse signals of the A output and the B output of the rotary encoder is executed on a periodic basis and then the pulse signals are transmitted via a network such as a wireless LAN (wireless Local Area Network). However, since a packet is transmitted with short periods, a problem arises in which a traffic is increased.
Although not in a field of the remote control device, in a field of an AC servo motor, there is known an art in which outputs of the A output and the B output from the rotary encoder are counted by an edge counter, the count value indicating a rotational position is transmitted by wired serial communication, and then signals of the rotary encoder are regenerated based on the received data.